1) Folders under "My Computer" are listed as \\server\share (Drive Letter). The drive letter is not displayed if the server name and share name is long. This makes it difficult for users whom are accustom to adding data from a specific drive letter. I don't think that most users know or care about the server name or share.
Please change so the add data dialog displays the drive letter first before the server name and share name.
2) The scroll bar is too narrow and hard to grab with a mouse.
3) The add data from a folder dialog displays every single drive that a computer is connected to in "My Computer" - even if the folder does not contain any GIS data. I presume this may be in response to users whom did not realize they needed to connect to a folder in ArcGIS 10.x. This effectively made it so that users went from having too few folder connections to too many folder connections. Consider allowing users to mark a folder as a favorite folder - similar to how connected folders in ArcGIS 10.x work. That way users may toggle between "favorite connections " (similar to ArcGIS 10.x) and "all connections" (similar to the current behavior)
4. I think adding data is now much more complicated than it needs to be. For example:
*Is a SDE connection a "Query Layer" or is it something else? I always thought that they were seperate. However I am not sure how to add a query layer.
*I am guessing we can add WMS, and WFS data by adding data from a path. Can we save these connections so we dont have to write down the URL to the services?